1. Field of the Invention
This invention relates to a method of installing a free standing, waterproof lining in a truck trailer, cargo container or the like. More specifically, this invention relates to a vacuum or suction assisted method of inserting a disposable polyolefin bag or film liner into a semi-trailer during loading of the trailer such as to protect moisture sensitive cargo.
2. Description of the Prior Art
The basic concept of providing a semi-truck trailer with a liner and ancillary support equipment has been generally proposed in the past for various reasons. For example, in U.S. Pat. No. 2,712,797 a bag like flexible container is disclosed mounted in a dump truck trailer wherein supporting means for collapsing the flexible container is provided such that the trailer can be used for bulk haulage of pourable material as well as for general hauling. U.S. Pat. No. 3,756,469 discloses a flexible liner used in a hopper vehicle, again where the flexible liner is supported within the trailer such that it is collapsible, allowing the trailer to be converted to general hauling. Other specialized applications for open topped trailer liners have been proposed such as in U.S. Pat. No. 4,186,845 wherein a foamed base sheet with polymeric top sheet is proposed for creating a tub within a trailer and U.S. Pat. Nos. 3,980,196 and 4,124,136 disclose flexible liners with framework and bulk head that essentially convert the trailer into a container for bulk cargo transport. Similarly, U.S. Pat. No. 3,951,287 discloses a flexible liner that is support within a conventional semi-trailer by stretchable connectors along the trailer sidewalls that essentially convert the trailer to bulk material shipping.
In contrast to the prior art concept of using a flexible liner for bulk handling, theoretically there are other applications for use of a liner within a trailer provided such liner would be intrinsically extremely inexpensive, be readily and conveniently installed without essentially any down time or significant additional labor costs and provided that no other significant health hazard or risk is associated with its use. For example, it is known and generally tolerated in the trailer industry that certain types of common and ordinary goods statistically incur significant water damage associated with conventional transportation procedures independent of continuing efforts to prevent such shipping damage. In particular, moisture damage to cigarette and other tobacco products during transportation is known to be a troublesome problem in the industry, as is moisture and water damage to various paper products and paper related articles directly attributable to leaks in the semi-trailer. Although damages associated with such occurrences can be considered a significant statistical risk and cost from an insurance industry viewpoint, the actual effectiveness of correcting the problem by conventional methods (e.g., better packaging, sealing leaks in the trailer, etc.) is cost prohibitive relative to insuring the risk. In principle, an essentially disposable liner that could be selectively installed in a semi-trailer on an as needed basis would represent an ideal solution. To the best of the present inventor's knowledge, no one has proposed a method of installing an essentially stand alone, disposable polyolefin film bag that could be installed in a semi-trailer on short notice and enclose the entire cargo.